(Sorry about this delayed reply on the topic - was offline for a week.)

Ah - I've been curious about the identity of the 'Silver Sword' Philo for ages.
Although I've seen it hanging around Sydney for about 20 years, I've only
rather recently seen any published picture or mention of it. I think the same
clone also goes by the names 'Silver', 'Silver Queen' and 'Blue Mink'. The
first plant I saw had been imported by a local grower of rare orchids, York
Meredith - his "very rare blue Philodendron" ("from Colombia", he thought) had
recently come through quarantine, & he was keen to show it off.

Anyway - just thought I should mention that my plants of this Philo are in
flower , and I'm intending to make a few observations, if that will help
confirm its ID as P. hastatum. (Unfortunately I don't have access to the
Lorenzi Burle Marx book...) I'll send a more detailed posting with
descriptions of my 'Silver Sword' (and maybe of a couple of apparently closely
related Philos) once I've had a good look at it. (I was also hoping to
photograph the inflorescences as close-up as possible, but the camera with
macro lens is at repairs for 2 weeks, so I might have to make do with
not-so-close-ups...)

Eduardo, I was also wondering if you could possibly suggest some taxonomically
important features - but easily observed ones! - that I should look out for in
the inflorescences (or in any other parts of the plant)?

I do have access to a dissecting microscope (up to 50x), but it's years since I
was a botany undergrad - and my dissection & microscopy skills have since gone
to pot! Back then I did examine flowers of this Philo & took notes of a few
details, e.g. number of locules per gynoecium, no. of ovules per locule, and
placentation - as the literature I'd looked up (Engler & Krause) seemed to
place stong emphasis on gynoecial things. However, I don't expect to be able
to manage anything that detailed now (and my old notes are long gone) - so are
there any kind-of gross morphological features, visible without needing much
dissection, that are just as useful for identifying these Philos?